The field of the present invention is valving associated with alarms to detect flow in piping.
Piping systems which maintain a charge of water such as fire sprinkler systems commonly employ alarm valves which indicate flow through the system. In turn, such flow indicates use of the system such as during a fire sprinkler discharge, fire hose activation or the like. The alarms associated with such systems are commonly mechanical in nature to activate a local gong. Switches associated with electric alarm circuits may also be employed. Such systems are designed to detect flow indicative of proper operation of the system. With a first sprinkler system, the flow detected may be in the range of 15 GPM and above. For example, a flow of 15 GPM might reflect the discharge of a single fire sprinkler associated with the piping system.
Such alarms are typically arranged in a vertical rise of pipe which includes a valve body having a seat and a pivotally mounted flapper valve. The seat typically employs a groove in the sealing face thereof extending fully thereabout. A vent from the groove extends to atmosphere through a restricting orifice, a retard chamber and a conventional flow alarm device. When the flapper valve is opened by flow through the piping, the groove is exposed to the liquid and a small amount of flow is allowed to pass through the restricting orifice and ultimately activate the flow alarm device.
Piping systems employing such valves such as fire sprinklers are charged with liquid and then sealed. The liquid, typically water from a community water supply, is heated by the ambient conditions about the system to raise the pressure within the piping above that of the supply. This results in the pressure within the system rising significantly above the pressure within the water supply. This rise is also greater than the often experienced spikes in pressure within such supply systems. This overpressure within the piping system maintains the flapper valve within the alarm valve closed.
Further, regulations also frequently require backflow preventers in fire sprinkler systems. The water within the piping is stagnant and can accumulate impurities and organisms detrimental to the integrity of a community water supply. Such backflow preventers are typically check valves such as a spring biased flapper held against a seat. Such backflow preventers are unable to be monitored for leakage. Further, they do not monitor the integrity of the alarm valve without removal. Even then, only substantial dysfunction in the backflow preventer is likely to be detected.
Many moisture and flow detection devices are commercially available for a variety of uses. One such device is referred to here as an accumulator alarm. A cavity having an opening from above receives moisture. The moisture is able to accumulate within the cavity until a liquid level switch is actuated. The actual mechanism may be a float associated with a microswitch, contacts of a circuit closed by the conductivity of the liquid or the like. Such devices are typically able to be drained and reset for repeated use.
The present invention is directed to an alarm valve system including a valve body with a valve element cooperating with a valve seat therein. The seat includes a groove in the face thereof extending to a vent. A flow alarm is in communication with the vent.
In a first separate aspect of the present invention, an accumulator alarm is also in fluid communication with the vent. Leakage flow not associated with system operation is, thereby, monitored. Reliance on the integrity of a blackflow preventer can be avoided.
In a second separate aspect of the present invention, an accumulator alarm in fluid communication with the vent is associated with the alarm valve system and includes a cavity having an opening from above. A liquid level switch is activated by the accumulation of water within the cavity. A drain valve may also be employed for convenient resetting of the switch.
In a third separate aspect of the present invention, a combination of the foregoing aspects is also contemplated.
Accordingly, it is an object of the present invention to provide an improved alarm valve system. Other and further objects and advantages will appear hereinafter.